1. Field of the Invention
The present invention relates to an apparatus for removing water vapor from air that enters a container (e.g. drum) containing a deliquescent liquid chemical product as the liquid contents are being withdrawn from the drum.
2. Description of the Prior Art
When liquid chemicals are pumped from a shipping drum or similar container, air or an inert gas (e.g. nitrogen) is drawn into the container to replace the withdrawn liquid. This is usually done by simply opening a bung on the top of the drum.
In the case of deliquescent liquid chemicals like polyacrylamide emulsions used in water treatment, the moisture in the air may cause the liquid to change its physical characteristics such as having a thicker viscosity and being difficult to pump. Moreover, some of the thickened chemical product may not be usable because it cannot be easily removed from the drum.
One solution to this problem is to displace the liquid with an inert gas (e.g. nitrogen) instead of air. However, such installations are relatively costly to set up and operate because they require the use of a container of compressed gas. Moreover, it is very cumbersome to connect and regulate the gas pressure from an inert gas cylinder every time a new drum of chemical is employed. This is especially so when the liquid chemical drum is being used in some inconvenient place such as in a typical water treatment application.
Accordingly, there is a need for a simple and inexpensive apparatus which allows dehumidified air to replace withdrawn liquid chemicals from a drum or similar container.